Rollback Modeling: Basic and Modified

The rollback or proportional model is widely used in pollution control calculations and included in the guidelines for preparing and evaluating state implementation plans. Its basis and limitations are not widely known or understood. In this paper, the basis and limitations of rollback are listed and discussed, and extensions of basic rollback are proposed.     

The UK landfill tax and the landfill tax credit scheme: operational weaknesses

The UK Landfill Tax and the related Landfill Tax Credit Scheme have now been in operation since October 1996. There have been a number of reviews to assess its operation and effectiveness that have led to some minor amendments. However, there continue to be concerns about operational weaknesses of the tax and the credit scheme. In particular, there is the risk that the tax may be evaded and there are fears that a lack of transparency and independence may undermine the fundamental principles of the Landfill Tax Credit Scheme. Following a recent report, the Secretary of State for the Department of the Environment, Transport and the Regions has set up an inquiry. This paper looks at some of the specific concerns that have been raised and the implications for waste management.     

Prenatal genetic counselling for psychiatric disorders

Psychiatric disorders like schizophrenia, bipolar disorder, depression, anxiety, and obsessive–compulsive disorder are common disorders with complex aetiology. They can exact a heavy toll on the individual with the condition and can have significant impact on family members too. Accordingly, psychiatric disorders can arise as a concern in the prenatal context – couples may be interested in learning about the chance for their child to develop the illness that manifests in the family and may be interested in discussing options for prenatal testing. However, the complex nature of these conditions can present challenges for clinicians who seek to help families with these issues. We established the world's first specialist genetic counselling service of its kind in Vancouver, Canada, in 2012, and to date, have provided counselling for ~500 families and have demonstrated increases in patients' empowerment and self efficacy after genetic counselling. We draw on our accumulated clinical experience to outline the process by which we approach prenatal genetic counselling for psychiatric disorders to assist other clinicians in providing thoughtful, comprehensive support to couples seeking out this service. © 2016 John Wiley & Sons, Ltd.     

Comparative diet selection by cattle and sheep grazing two contrasting heathland communities

In the UK the funding mechanism for moorland restoration is being implemented primarily through agri-environment schemes, yet to date remarkably few comparative grazing studies with domesticated livestock have been conducted on this type of vegetation community. In this experiment the diet composition of four groups of animals grazing heathland swards with low (8%) and high (61%) percentages of cover of Calluna vulgaris was estimated from faeces profiles of n-alkanes and long-chain fatty alcohols. Two breeds of sheep (Welsh Mountain (WM) and Scottish Blackface (SBF)), and two breeds of cattle (Welsh Black (WB) and Continental cross (CX)) grazed the experimental sites during two separate 14-day sampling sessions, in July and September respectively. Both species were selective feeders, consuming grasses (selectivity indices 0.20–1.0) in preference to dwarf shrubs (selectivity indices 0.20–1.0), but there were significant differences in the proportions of various plant groups within the diets. Although the sheep diets contained significantly more C. vulgaris, the quantities consumed were small (<10% of the diet), even on the High site, reflecting the biomass of the graminoid species present, and hence availability of preferred items. The SBF sheep were the only animal type to increase consumption of C. vulgaris later in the season. There were a number of significant differences in the composition of the diets selected by the two hill breeds of sheep used in the study, with the SBF sheep recorded as consuming more C. vulgaris. These results imply that through choice of breed land managers may be able to meet environmental goals more effectively without compromising returns from conventional production systems. In contrast, the overall diet composition of the two breed types of cattle was similar. This indicates that commercial breeds have the potential to deliver the types of environmental benefits associated with grazing of traditional breeds.     

The innate responses of bumble bees to flower patterns: separating the nectar guide from the nectary changes bee movements and search time

Nectar guides can enhance pollinator efficiency and plant fitness by allowing pollinators to more rapidly find and remember the location of floral nectar. We tested if a radiating nectar guide around a nectary would enhance the ability of naïve bumble bee foragers to find nectar. Most experiments that test nectar guide efficacy, specifically radiating linear guides, have used guides positioned around the center of a radially symmetric flower, where nectaries are often found. However, the flower center may be intrinsically attractive. We therefore used an off-center guide and nectary and compared “conjunct” feeders with a nectar guide surrounding the nectary to “disjunct” feeders with a nectar guide separated from the nectary. We focused on the innate response of novice bee foragers that had never previously visited such feeders. We hypothesized that a disjunct nectar guide would conflict with the visual information provided by the nectary and negatively affect foraging. Approximately, equal numbers of bumble bees (Bombus impatiens) found nectar on both feeder types. On disjunct feeders, however, unsuccessful foragers spent significantly more time (on average 1.6-fold longer) searching for nectar than any other forager group. Successful foragers on disjunct feeders approached these feeders from random directions unlike successful foragers on conjunct feeders, which preferentially approached the combined nectary and nectar guide. Thus, the nectary and a surrounding nectar guide can be considered a combination of two signals that attract naïve foragers even when not in the floral center.     

The importance of group‐focused transformational leadership and felt obligation for helping and group performance

Leaders face a challenge to simultaneously motivate workgroups and the individuals within them. Recent criticisms highlight the need to deconstruct broad leadership constructs to offer better theoretical insight into the effects of specific leadership behaviors on groups versus individuals. We address this call by exploring the effects of group‐focused and individual‐focused aspects of transformational leadership. Applying social identity theory, we theorize that group‐focused transformational leadership is key to fostering felt obligation, motivating helping behavior, and enhancing group performance, whereas individual‐focused leadership may only foster helping when individuals also feel a sense of obligation toward their workgroup. In a field study of 260 employees reporting to 36 supervisors in a skilled trade company, we find support for these predictions using multilevel structural equation modeling and multilevel mixed effects modeling. Thus, group‐focused (vs. individual‐focused) transformational leadership and subsequent felt obligation are important antecedents for encouraging helping and, in turn, workgroup performance.